is_versor

ahrs.common.quaternion.QuaternionArray.is_versor(self) → ndarray

Returns an array of boolean values, where a value is True if its corresponding quaternion has a norm equal to one.

A versor is a quaternion, whose euclidean norm is equal to one: \(\|\mathbf{q}\| = \sqrt{w^2+x^2+y^2+z^2} = 1\)

\[\begin{split}\left\{ \begin{array}{ll} \mathrm{True} & \: \sqrt{w^2+x^2+y^2+z^2} = 1 \\ \mathrm{False} & \: \mathrm{otherwise} \end{array} \right.\end{split}\]

Returns:

out – Array of booleans.

Return type:

np.ndarray

Example

>>> Q = QuaternionArray(np.random.random((3, 4))-0.5)
>>> Q[1] = [1.0, 2.0, 3.0, 4.0]
>>> Q.view()
QuaternionArray([[-0.8061095 ,  0.42513151,  0.37790158, -0.16322091],
                 [ 1.        ,  2.        ,  3.        ,  4.        ],
                 [ 0.29613776,  0.21692562, -0.16253866, -0.91587493]])
>>> Q.is_versor()
array([ True, False,  True])